It says the number was an estimate, but doesn't say how it was estimated.

Most of the study session was spent talking about the latest retirement cost projection of $320 million and looking at pessimistic scenarios and how their occurrence could affect pension projections.

District 2 Councilman Ash Karla spoke with us after the meeting and said, the memo explaining the $650 million projection has only raised more questions.

"I don’t think the memo directly answered the questions," Kalra said, "it gave the overall sentiment that these numbers were off the top of his head and the staff encourages that kind of dialog and I encourage that type of dialog too, but when numbers taken from that dialog are used so publicly we need to know how much we can rely on those numbers."

Kalra also said the public use of the estimate, makes it important to know their derivation.

"In this case it doesn’t seem those numbers should have been relied upon, but they were relied upon very publicly. So why was no one told they shouldn’t haven’t been replied upon?"

City Manager Debra Figone was not present at the meeting.

Deputy City Manager Alex Gurza told us he did not have time to talk with us today.